Now, about aperture. I know that a low aperture setting is for bokeh, and a high one will give you those twinkle-y lights when you take pictures at night.

But other than that, How do you know where to set them? I've been taking most of my daytime pictures at a low setting, and my nighttime ones at a high one. Is that a good approach? I do switch it up sometimes.

When are you supposed to use a "middle setting"?

I know this makes me look pretty dumb, but I AM new to this after all. :blushing:

Typically shooting wide open isn't the sharpest. For example, when I shoot birds I typically shoot in the f/4 - f/8 range. A lot also depends on the distance from the object, ambient light and background (distance from object to background as well).

FYI, bokeh is just the out of focus area of your photo. The lower the number the more out of focus area you'll have.

If you can get your hands on a copy of the book understanding exposure it will go a long way. Heres my explanation from one beginner to another. In short the higher the f number the more of the photo that will be in focus. Most lenses will be sharpest in the middle. If you have a subject that you want in focus and you want the background blurry use a lower f number (1.8-5 something). If you are shooting something and the background is close to the same distance away as the subject (like a shell on the beach, or a person standing against a wall) then a middle range f number would be good (8-11). If you are shooting an outdoor scene like of a house where there is a mailbox, then the yard, then the house, and then a mountain range in the back and you want it all as much in focus as possible then a higher f number should be used 16+.
Of course this can all change if you have poor lighting or subjects are in motion and you need to change the shutter speed.
Again the book is a must for beginners like me (I read it twice in a week and will probably read it again after I have some time to get out and practice.